Engine starter gearing



y 1959 c. A. MENDENHALL 2,335,894

ENGINE STARTER GEARING Filed March 23, 1956 v IN VEN TOR. cad/168mm?WITNESS 2m. 92%; V iaxfi TOHNE Y ted. StatcsP .0"

ENGINE STARTER GEARIN G Charles A. Mendenhall, Horseheads, N.Y.,assignor to Bendix Aviation Corporation, a corporation of DelawareApplication March 23, 1956, Serial N 0. 573,377

4 Claims. (Cl. 74-6) The present invention relates to engine startergearing and more particularly to that type in which a pinion is shiftedmanually or electro-magnetically into and out of mesh with a gear on theengine to be started.

The presently prevailing demand for high gear ratios from the startingmotor to the engine crank shaft has forced the reduction in size of thedriving pinions to the point where any future reduction necessitates theuse of a solid pinion. Satisfactory maintenance of alignment and spacingof such a pinion, however, presents a problem, especially in view ofprevailing overall space limitations.

It is an object of the present invention to provide novel startergearing of the above type incorporating a solid pinion withself-contained supporting means for the pinion.

It is another object to provide such a device having a bearing on themotor shaft for rotatably supporting the pinion and additional clampingand supporting means for assisting in maintaining alignment during thecranking operation.

It is another object to provide such a device incorporating anoverrunning clutch located closely adjacent the pinion to reduce themass of the overrunning parts and therefore secure improved performance.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. 1 is a side elevation partly broken away and in section of apreferred embodiment of the invention with the parts shown in idleposition; and

Fig. 2 is a similar view showing the parts in cranking position.

In Fig. l of the drawing there is illustrated a power shaft 1 which maybe the extended armature shaft of a starting motor not illustrated. Theshaft 1 is formed with a splined portion as indicated at 2, and a sleeve3 is slidably but non-rotatably mounted on said splined portion.

A bearing member 4 is rigidly mounted on the end of the motor shaft 1 asby means of a cross pin 5, and a cup member 6 having a pinion 7 rigidlymounted thereon is slidably journalled on the bearing 4 for movement ofthe pinion into and out of mesh with a gear 8 of the engine to bestarted.

The sleeve 3 is provided with a terminal radial flange 9 having inclinedcoupling teeth 11 adapted to cooperate with similar teeth 12 on atransmission member 13 having a slidable bearing on the cup member 6.The transmission member is also provided with over-running clutch teeth14 adapted to engage similar teeth 15 on a flange ring 16 which isrigidly mounted on the exterior of the cup member 6 in any suitablemanner as by brazing as indicated at 17.

A barrel member 18 surrounds both said flanges and the transmissionmember 13, and bears slidably on the flange 9 of sleeve 3 and on saidtransmission member.

2,885,894 Patented May 12,-?'9

2 1 A thrust bearing ring 19 for the flange ring :16 isloosely mountedin one end of the barrel member and is retained in the barrel by a lockring 21. A compression spring in the form of a plurality of elastic discmembers 22 is located within the barrel adjacent its opposite end and iscompressed against the flange 9 of the sleeve by a a thrust disc 23retained in the barrel by crimping in the end of the barrel as indicatedat 24. Expansion of the spring 22 is limited by a lock ring 25 seated inthe sleeve 3 in position to engage the thrust disc 23.

Means for shifting the sleeve 3 to move the pinion 7 and its associatedparts into and out of meshing position is provided comprising a shiftingfork 26 which may be manually or electro-magnetically operated, and isprovided with trunnions 27 operating in a shift collar 28 which isretained on the end of the sleeve 33 by a lock ring 29. A spring 31 isarranged to yieldably transmit the movement of the shift collar 28 tothe thrust disc 23.

In operation, starting with the parts as illustrated in Fig. l, movementof the shift fork 26 to the right is transmitted through the shiftcollar 28 and spring 31 to the sleeve 3 by means of thrust disc 23 andspring 22. This movement is transmitted through the transmission member13 to the flange ring 16, cup 6 and pinion 7 to move the pinion intomeshed position as shown in Fig. 2. When the motor is energized, thetorque transmitted through the coupling elements 11, 12 forces thetransmission member 13 to the right, thereby clamping the flange ring 16tightly in the barrel whereby the cup 6 is held rigidly in alignmentwith its bearing 4 on the motor shaft. The reaction of this clampingpressure is taken by the thrust spring 22 which may permit the couplingelements 11, 12 to ride over each other and thereby reduce the initialshock.

When the engine starts, the overruning action permits the transmissionmember 13 to move back toward flange 9 of sleeve 3, thus permitting theoverrunning clutch teeth 14, 15 to disengage and allow the pinion tooverrun until such time as the pinion is drawn back out of mesh byrelease of the shifting fork 26.

Although but one embodiment of the invention has been shown anddescribed in detail it will be understood that changes may be made inthe design and arrangement of the parts without departing from thespirit of the invention.

I claim:

1. In engine starter gearing a motor shaft, a sleeve splined thereon, abearing member fixed on the end of the shaft, means for traversing thesleeve on the shaft toward and from said bearing member, a cup memberslidably journalled on the bearing member, a pinion rigidly mounted onthe end of the cup member beyond the end of the shaft and movablethereby into and out of mesh with a gear of the engine to be started, aradially extending flange member rigidly mounted on the cup memberadjacent the pinion, and means responsive to rotation of the sleeve forclamping the flange and cup member coaxially to the sleeve.

2. Starter gearing as set forth in claim 1 in which the splined sleeveis formed with a terminal flange, and the means for clamping the flangeand cupmember to the sleeve includes a barrel member slidably mounted onthe sleeve flange and extending over the cup flange, means in the barrellimiting separation of the two flanges, and a transmission memberintermediate said flanges having wedging engagement therewith.

3. Starter gearing as set forth in claim 2 in which the flange on thesplined sleeve is formed with inclined torquetransmitting teethcooperating with similar teeth formed on said intermediate transmissionmember.

means for clamping the flange and cup member to the sleeve includes aring mounted in the barrel having a radial surface forming a ihrustbearing for the cupmounted-flange. l

References Citedln the file of this patent UNITED STATES PATENTS

